Energy Consumption and Greenhouse Emissions
The historical and projected energy consumption by gas space heaters in Australia and New Zealand has been estimated using a stock/sales model that is combined with various appliance and usage attributes. The total estimated Australian annual energy consumption by gas ducted heaters is shown in Figure with energy consumption estimated to decline from 27 PJ pa in 2000 to 14 PJ pa in 2020. The decrease in energy consumption is largely due to the decreasing in the stock of gas ducted heaters, especially of wall furnaces.
Figure : Space Heater Annual Energy Consumption by Category 2000 – 2020- Australia
The estimated natural gas and LPG consumption from space and decorative heaters are shown in the Table and Table . These indicate an approximate consumption of 2.3 PJ in 2007/08 of LPG and natural gas in combination. The trends for LPG between 2006 and 2008 also suggest a decline in gas space heating is occurring.
Table : Natural gas home heating energy use- New Zealand
Type of burner
|
Energy consumption
PJ/ year, 2007
|
Space Heaters (excluding central heaters and decorative appliances)
|
1.03
|
Decorative Appliances
|
0.11
|
Total
|
1.14
|
Source: Environet 2009
Table : Bottled and piped LPG home heating fuel consumption and energy use- New Zealand
|
2006
|
2008
|
Burner Type
|
Households
using
|
Annual fuel consumption
Tonnes/ year
|
Total PJ/ year
|
Households No.
|
Annual fuel consumption
Tonnes/ year
|
Total PJ/ year
|
Space Heaters
|
325,683
|
45,684
|
2.3
|
163,894
|
22,890
|
1.1
|
Decorative Appliances
|
9,310
|
1,341
|
0.1
|
9,310
|
1,341
|
0.1
|
Total
|
334,993
|
47,025
|
2.4
|
173,204
|
24,231
|
1.2
|
Source: Environet 2009
The estimated greenhouse gas emissions for Australia by category from 2000 to 2020 are shown in Figure .
Figure : Space Heater Annual Greenhouse Gas Emissions by Category, Australia 2000– 2020 (kt CO2-e)
The greenhouse gas emission estimates for New Zealand from natural gas and LPG residential heaters and decorative appliances are shown in Table .
Table : Summary of Greenhouse Gas Emissions by Fuel: Residential Gas Space Heaters and Decorative Appliances
Fuel Source
|
Total
(kt CO2-e /yr)
|
Space Heaters
(kt CO2-e /yr)
|
Decorative Appliances
(kt CO2-e /yr)
|
Radiant Outdoor Heaters
(kt CO2-e /yr)
|
Natural Gas (2008)
|
74
|
54
|
6
|
1
|
LPG (2007)
|
166
|
137
|
4
|
8
|
Total
|
240
|
191
|
10
|
9
|
Source: Environet 2009
Stock and Sales Trends
The number of households who use non-ducted gas space heaters as their main form of heating has decreased during the period from 2002 to 2008, according to data from the ABS 4602 time series reports. These reports shows that the number of households using non-ducted gas heating has declined by 6.5% from 2002 to 2008. This is a decline of approximately 1% per annum. This is reflected in Figure .
Figure : Estimated Stock of Gas Space Heaters by Category 2000 - 2020
Source: ABS 4602 from 2002, 2005, 2008
The sales by category of gas space heater from 2006 to 2008 in Australia are presented in summary form in Table .
Table : Sales of Gas Space Heaters, Australia (2006 - 2008)
-
Category
|
2006
|
2007
|
2008
|
Balanced Flue Convection Heaters
|
2,811
|
3,466
|
3,955
|
Decorative*
|
10,000
|
10,000
|
10,000
|
Flued Radiant/Convection Heaters
|
4,699
|
4,631
|
4,268
|
Flueless Convection Heaters
|
31,303
|
30,058
|
30,935
|
Flueless Radiant/Convection Heaters
|
19,817
|
20,948
|
18,934
|
Wall Furnace
|
2,851
|
2,764
|
2,638
|
Total
|
71,481
|
71,867
|
70,730
|
* Decorative is based on industry estimate. Source GfK 2008.
The information on stock and sales trends have been used to develop sales forecasts for Australia, shown in Figure . They suggest a decline in annual sales, but that significant sales will continue for the next ten or more years.
Figure : Estimated Sales of Gas Space Heaters by Category 2000 – 2020- Australia
For New Zealand, there is less information available on decorative and space heating sales and stock. Table clearly indicates a decline in the use of gas heating, for the period 2005 to 2008 but imports of gas heaters had been growing till 2007, so it is possible that the decline in 2008 may be the result of short term economic conditions due to the global financial crisis. The total number of gas and dual fuel heaters imported into New Zealand in 2007 is estimated to be around 70,000 units, but the number of sales of New Zealand manufactured units in unknown. Approximately half of these units were portable LPG gas heaters.
Table : Reported home heating methods, main living area, 2008 and 2005- New Zealand
|
2008 Heating Methods
|
2005 Heating Methods
|
|
%
|
Total
|
Mains
|
Bottled
|
%
|
Total
|
Mains
|
Bottled
|
Total Flued gas
|
8%
|
123,121
|
75,999
|
63,181
|
9%
|
134,939
|
82,462
|
52,476
|
Flame effect – Flued
|
2%
|
31,151
|
25,076
|
12,395
|
|
|
|
|
Other Space Heater - Flued
|
4%
|
91,970
|
28,947
|
34,304
|
|
|
|
|
Unflued gas
|
13%
|
185,423
|
42,244
|
127,120
|
24%
|
352,339
|
59,973
|
292,367
|
Total Gas
|
21%
|
308,543
|
118,242
|
190,301
|
36%
|
487,278
|
142,435
|
344,843
|
Regarding the stock trends for New Zealand, if it is assumed the households connected to reticulated gas use gas space heating, and the number using portable gas heaters is added, then a total of 625,000 used gas space heating in 2007, though this number would have declined in 2008. Import data suggests that in 2007 imports are around 20,000 p.a. more than is required to satisfy the need to meet existing stock turnover. This suggests the New Zealand stock of gas space heaters was growing up until 2007, but if the decline in imports in 2008 has continued as a trend, then the stock numbers will have stabilised.
Market Structure
For Australia, there are 31 suppliers of gas space heaters and decorative appliances listed in the AGA Certified Product Directory (Aug 2008)11, with over 40 brands and more than 190 models12. Flued radiant/convection heaters have 88 models listed followed by decorative appliances with 38 models.
Approximately half of the suppliers manufacture these units in Australia, which represents 40% of total number of models in the AGA Certified Product Directory. The major countries of origin of the imported models are Japan, USA and New Zealand. For decorative appliances, Australia and the USA represent the major source of models on the market.
Analysis of the GfK sales data from 2006 to 2008 shows that the vast majority of gas space heater sales are dominated by Rinnai, Everdure, Paloma and Vulcan. An estimated 70% of the units sold in the market are imported.
For New Zealand, there are 18 suppliers and/or importers of gas space heaters and decorative appliances . There are 27 companies that manufacture gas heating appliances for the New Zealand market and a third of these are New Zealand based. However, the proportion or number of space heaters manufactured in new Zealand is unknown. Import data suggests around 75% of gas space heaters imported are imported from China and almost none are manufactured in Australia, with the rest from Argentina, Canada, the United Kingdom, the United States of America, Norway, Canada, Japan and South Africa.
Efficiency Trends
The sales weighted average thermal efficiency for space heaters was determined for Australia for space heaters by category from 2006 – 2008, as shown in Figure . No such data was available for New Zealand.
Figure : Sales Weighted Average Net Efficiency by Category 2006 – 2008- Australia
It appears that average net efficiency of appliances is relatively stable, but this analysis is based on only three years of data, so it is difficult to determine if any changes represent long term trends. The net efficiency of flueless convection and radiant/convection heaters is close to their theoretical maximum of 90.4%.
Table : Sales Weighted Average Net Efficiency by Category 2006 -2008- Australia
-
Category
|
2006
|
2007
|
2008
|
Balanced Flue Convection Heaters
|
81.08%
|
80.99%
|
80.91%
|
Flued Radiant/Convection Heaters
|
71.53%
|
72.75%
|
73.58%
|
Flueless Convection Heaters
|
89.86%
|
89.90%
|
89.91%
|
Flueless Radiant/Convection Heaters
|
90.38%
|
90.36%
|
90.37%
|
Wall Furnace
|
71.70%
|
69.60%
|
69.63%
|
Decorative*
|
15%
|
15%
|
15%
|
Total (excluding Decorative)
|
87.42%
|
87.40%
|
87.50%
|
Total (including Decorative)
|
77.27%
|
77.31%
|
77.14%
|
*Decorative net efficiency determined from product information on heat output and input gas consumption
Source: Analysis of GfK Sales and AGA model data
The range of star ratings by model and gas input (MJ/h) is shown in the following figures for each category of heater in Australia. The heaters listed in these figures are the models that are currently on the market for the period 2006 to 2008. No data was available for models sold in the New Zealand.
Although there is a range of efficiency over the five categories of heaters, the flued radiant/convection heaters show the largest spread of star ratings by model, while the flueless heaters provide the smallest range of star rating.
Figure : Star Rating by Model and Gas Input - Flued Heaters
There is sufficient variation in the efficiency of the gas space heaters on the market for a gas label to convey useful information to consumers for the flued categories. There is a wide range of star ratings for flued radiant/convection heaters, with a spread of models from 1 to almost 6 stars. This indicates that there is potential for consumers to choose a more efficient heater from the available models. Balanced flue convection heaters are designed to draw air for combustion from outside the home and heat is transferred to the room via a heat exchange. These types of heaters are generally more efficient and all models are 4 stars or more, as shown in Figure . Wall furnace type heaters range from 1 to 3.5 stars.
The flueless heaters provide the smallest range of star rating and are bunched between the 5 and 6 star rating (Figure and Figure ). However, some stakeholders including government consider the flueless heater ratings are misleading and testing and rating should include an allowance for room ventilation in their calculation, which if implemented might lead to a greater spread in their ratings.
Figure : Star Rating by Model and Gas Input - Flueless Convection Heaters
Figure : Star Rating by Model and Gas Input - Flueless Radiant/Convection Heaters
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